Avis Budget Group Inc. will pay $12.25 per share, which is a 49 percent premium to the company's Friday closing price. The companies put the total value of the deal at approximately $500 million.

Zipcar Inc. has about 40.1 million outstanding shares, according to FactSet. It will become an Avis subsidiary and have headquarters in Boston. Shares jumped more than 6 percent in premarket trading Monday.

The boards of both companies unanimously approved the buyout.

Avis, based in Parsippany, N.J., anticipates $50 million to $70 million in annual savings.

If Zipcar shareholders approve the deal, it's expected to close in the spring.